Feeding mechanism for sewing-machines.



A. GRIEB. FEEDING MEGHANISM FOB. SEWIN MACHINES. APPLICATION FILED sBPT.11, 190s.

Patented sept. 5,1911.

2 BHEBTB-SHEET l.

www W ATTORNEY cOLLMBm PLANoGzAvlI Co., WASHINGTON. nA c.

A. -GRIEB. FEEDING MBGHANISM ron SEWING MACHINES. I APPLICATION FILED SEPT.11, 1906. l

Patented Sept. 5,1911.

2 BHBETS-BHEET 2.

coLuMBlA PLANUDRAFH co.. WASHINGTON. D. c.

UNITED STATES PATENT GFFIQE.

ALFRED GRIEB, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SING-ER MANUFAC- TURING COMPANY, A CORPORATION 0F JERSEY.

FEEDING- MEGHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Application filed September 11, 1908.

To all whom it may concern:

Be it known that I, ALFRED GRIEB, a citizen of the United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Feeding Mechanism for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to an improvement in that class 0f dierential feeding mechanism designed especially for operation upon knit goods, to prevent distortion in the stitchforming and feeding operations, forming the subject of the United States patent to P. Diehl and A. Grieb, No. 814,027, of March 6, 1906; and it has for its object to provide mechanism of the class described which shall be more effective and more readily adjusted.

According to the present improve-ment, the feeding mechanism comprises two pivotally connected feed-bars each carrying a feed-dog and provided with suitable initialv lifting means and with actuating means for imparting thereto simultaneous feeding movements, the connection with said actuating means of one of the feed-bars being so constructed and arranged as to impart additionally to its respective feed-dog rising and falling movements relative to those of the other feed-dog. It also includes a readily accessible device carried by said actuating means for varying the relative rising and falling movements of the feed-dogs. It further includes a presser-foot of special form for coperating with the differentially acting feed-dogs in effectively feeding the work to and beyond the stitch-forming mechanism.

In the drawings, Figure 1 is a transverse sectional elevation of a Singer overseaming sewing machine embodying the present improvements. Fig. 2 is a plan representing separately the feeding mechanism, and Fig. 3 a sectional elevation of the operative mechanism for the feed-rocker. Fig. 4 is a perspective view, partly in section, and Fig. 5 a plan of the presser-foot, and Fig. 6 a front view of the presser-foot. representing in section the throat-plate and feeddogs in the positions of such parts shown in Fig. 1

The machine frame comprises the base 1 and overhanging bracket-arm 2 in which is j ournaled the transverse inclined rock-shaft 3 with forwardly extending arm 4 connected by means of the forked link 5 with the collar 6 lixed upon the needle-bar 7 which carries the needle 8. The primary looper 10, which seizes the thread-loops from the `needle beneath the throat-plate 9, is secured within the carrier 11 mounted upon the fulcrum-stud 12 ixed in the base 1; and the secondary looper 13 is xed upon the carrier 14 suitably journaled within the bed for oscillatory movement in a plane parallel with the similar movements of the primary looper at an angle with the inclined needle 8, and is adapted to take loops from the primary looper and to present loops above the throatplate for passage of the needle, all as shown and described in my pending application Serial No. 368,035. The means by which the needle and loopers are actuated from the main-shaft are not shown herein, as they form no part of the present improvement.

The main or primary feed-bar 15 has fixed upon its forward end the primary feeddog 16 and is connected adjacent the same by means of a pivotal pin 17 to the upper end of an eccentric-rod 18 having upon its lower end the strap 19 embracing the feedlifting eccentric 20 upon the main-shaft 21 extending longitudinally through the machine. At its rearward end the primary feed-bar is secured by means of a set-screw 22 to a transverse pin 23 journaled in the upwardly extending ears 24 of the feedrocker connected by means of the sleeve 25 which is journaled upon the shaft 26 mounted in bushings 27 within suitable bearing brackets 28 at the rearward side of the frame.

Upon one end of the sleeve 25 of the feedrocker is adjustably secured a lateral crankarm 29 which is pivotally connected with the upper end of a link 30 whose lower end carries a block 31 adjustably secured by wellknown means within a circular groove 32 in the segmental arm 33 of an angular lever mounted upon a fixed fulcrum 34 and having an upwardly extending arm 35 which is connected by a pivotal pin 36 with one end of an eccentric-rod 37 provided with a strap 38 embracing the feed-actuating eccentric 39 upon the main-shaft 21, as indicated in my said application. As will be observed, the shifting of the lower end of the link 30 toward or from the fulcrum-pin 34 serves to diminish or increase the rocking movements imparted to the feed-rocker from the eccentric 39, and communicates corresponding variations in the feeding movements of the primary feed-dog derived therefrom.

Adjacent the fulcrum-pin 17 the primary feed-bar carries a shouldered screw serving as a fulcrum-stud upon which is mounted the rock-lever, constituting an auxiliary feed-bar 4l, which carries at its forward end the auxiliary feed-dog 42 disposed rearward of the lateral feeding surface of the primary feed-dog upon the side toward which the looper-thread loops are carried by the secondary looper for passage of the needle. At its rearward end the auxiliary feed-bar is connected by means of a pivotal-pin 43 with the forward end of a bent link 44 whose opposite end is connected by means of the stud-screw 45 with a forwardly projecting arm 46 of a bent lever whose stem 47 is fulcrumed by means of the stud-screw 48 upon the feed-rocker rearward of the sleeve 25. The lever 46 47 has a depending finger' 49 with rounded extremity 50 entering an annular groove or recess 5l in the head 52 of an adjusting screw 53 tapped into a depending lug 54 of the feed-rocker transversely of its supporting shaft 26.

In the normal operation of the machine, the feeding movements of theprimary feeding member are communicated bodily to the auxiliary feeding member through the pivotal connection of the two feed-bars, but as the primary feed-bar is connected to the feed-rocker directly above its axis of oscillation, while the auxiliary feed-bar is connected thereto through the link 44 at a point disposed in advance of the axis of motion of the feed-rocker the rising and falling movements of the auxiliary feed-dog in relation to those of the primary feed-dog are determined by the position of the stud-screw 45, which receives risingand falling as well as lateral movements from the feed-rocker. It will thus be seen that the feed-bar 4l receives rocking movements upon its supporting stud 40, serving to communicate to the auxiliary feed-dog 42 rising and falling movements in relation to the primary feeddog 16; the arrangement of the stud 40 between the pivotal pin 23 and the operative faces of the feed-dogs, and remote from said surfaces in the direction of seam, being such that the tilting movement of the lever 4l thereon involves the rising and falling of its forward end carrying the feed-dog 42 rather than the movement thereof in the direction of feed. As will be readily understood, the degree of relative rising and falling movements between the feed-dogs 42 and 1G is determined by the distance of the stud-screw 45 in vadvance of the pivotal pin 23, and this is readily varied by turning the adjusting screw-head 52 to shift the bent lever 4G 47 upon the feed-rocker. To prevent the accidental shifting of this bent lever through the working of the screw 53 in the continued operation of the machine, the lever 46 47 is provided with a transverse slot 55 which is entered by the shank of a set-screw 56 tapped into the feed-rocker and adapted to clamp the bent lever in fixed relation therewith after its proper adjustment.

The primary feed adjustment, effecting the feeding or work advancing movements of the primary feed-dog 16 and the auxiliary feeddog 42, is preferably aecomplished in the positions of the parts wherein the primary feed-dog is at its extreme position in readiness for a feeding action and the segmental grooved or slotted arm 33 of the actuating mechanism is in its lowered position in which it is concentric with the pivotal connection between the upper end of the link and the lateral arm 29 of the feed-rocker. To the upper end of the link 30 is secured by means of the screw 57 the foot or shank 58 of a pointer arm 59 adapted, when the parts are in the described positions, to overlie the lower margin of a segmental scale-plate 60 provided with suitably numbered graduations to indicate the number of stitches per inch for the various adjustments of the block 3l carried by the lower end of the link 30 within the groove or slot 32 of the arm 33, such scale-plate 60 being provided at opposite ends with feet secured by means of screws 6l to the workplate 62 of the machine. -While-the primary feed-actuating mechanism and the indicator therefor, composed of the pointer 59 and scale-plate 60, are herein represented in connection with and adapted to control both operative members of a compound feeding device, it is evident that they may be readily employed in connection with a simple feeding device employing a single feed-bar l5.

The bed of the machine is provided with an upwardly extending bearing plate G3 carrying a lateral fu'lcrum-pin 64 upon which is mounted the boss 65 of the forwardly extending presser-bar 66 provided at its forward end with a transverse seat to which is securedby means of the fastening screw G7 and washer 68 the laterally extending forked lug 69 of the presser-foot shank 7() having rigidly connected therewith the forwardly extending toe portion 71 overlying the primary feed-dog 16 and provided with a lateral notch or recess upon the side on which the overseam is formed by the stitchforming devices. Within the notched or recessed portion of the rigid presser-foot member is disposed the usual chaining finger 72 having its angularly disposed foot-plate 73 secured thereon by means of the fastening screw 74.

The presser-foot shank is provided in its lower portion with a rearwardly extending perforated lug to which is secured by means of the pivotal pin 7 6 the forked rearward end of the forwardly extending heel portion 77 which is disposed rearwardly of the laterally extending portion of the foot and provided with a channel 7 8 having at one side the depending lip 7 9 and at the other side a depending rib 80 with forwardly extending finger 81. The heel portion 77 is arranged to overlie the auxiliary feed-dog 42, with its channel 7 8 in substantial alinement with the chaining finger 72, but extends laterally so that the finger' 81 of the rib 80 is adapted, when the auxiliary feeding member is lowered, to rest upon the margin of the throat-plate adjacent the feeddog opening 82 therein. The presser-foot shank 70 is provided with a vertical aperture in the upper portion of which is adjustably secured by means of the set-screw 83 the thrust-pin 84 intermediate whose lower end and the top of the heel portion 79 is interposed the spring 85 for normally pressing such heel portion downwardly. The rearward end of the heel port-ion 77 is provided adjacent the pivotal pin 76 with an upwardly projecting stop linger 86 whose forward side rests against the rear of the presser-foot shank and serves to limit the downward movement of the heel portion under the action of the spring 85.

In the operation of the machine, after the formation of an voverseam stitch, and while the needle is raised, both feed-dogs rise and effect their advance or feeding movementand yielding presser-foot members. Before the end of this feeding movement.l the auxiliary feed-dog 42 drops and is followed by the yielding presser-foot member 77 until the rib 80 rests upon the throat-plate or the material lying upon the same, thus offering an obstruct-ing shoulder to the advance of the work under the continued operative movement of the primary feed dog in conjunction with the coacting toe portion of the presser-foot, thus crowding the material against the forward portion of the presser-foot member 77 beneath the needle. As the primary feed-dog 16 drops, the presser-foot member 7l detains the material upon the throat-plate along the margin of -the primary feed-dog aperture 82, and the needle descends through the material thus crowded together at the stitching point and a succeeding stitch is formed.

It has been found desirable in practice to apply substantially the full power of the pressure spring 87 to the toe portion or primary member lof the presser-foot in order to insure certainty of action of the primary feed-dog upon the material in advancing the same la full stitch length for each feeding movement, while a slight pressure upon the heel portion or secondary member yof the presser-foot is sufficient-to afford the requisite retardation of the feeding action when the auxiliary feed-dog 42 is lowered. By forming the presser-foot section 77 with a channel 7 8, not onlyis the chain or overseam permitted to pass freely beneath the same, but the drag which would otherwise be applied to the thickened overseamed edge of the fabric by the presser-foot is avoided, and the consequent cramping of the margin of the material, especially in operation upon knit goods, is obviated.

From the foregoing description, it is obvious that the present improvement is susceptible of considerable modification, both in the construction and arrangement of the various parts of the differential feeding mechanism and of the coperating presserfoot, without departure from the present invention, although the embodiment of the same herein shown and described is considered preferable.

Having thus set forth the nature of the invention, what I claim herein is l. In a sewing machine, the combination with a feed-bar, a primary feed-dog carried thereby, actuating means connected with the feed-bar for imparting to the primary feeddog feeding movements in the direction of seam, and means connected with the feedbar for imparting to said feed-dog rising and falling movements, of a rock-lever pivotally mounted upon the feed-bar at a p'bint remote from said feed-dog in the direction of seam and bodily movable with the same, in conjunction with their superposed rigid an auxiliary feed-dog fixed to said rocklever, and means for tilting said rock-lever to vary the height of the operative surface f of the auxiliary feed-dogv relatively to that of the primary feed-dog.

2. In a sewing machine, the combination with a feed-bar, a primary feed-dog carried thereby, actuating means connected with the feed-bar for imparting to the primarv feed-dog feeding movements in the direction of seam, and means connected with the feed-bar for imparting to said feed-dog rising and falling movements, of a rocklever. an auxiliary feed-dog fixed to said rock-lever, a fulcrum-pin fixed upon said feed-bar intermediate its point of connection with said actuating means and the primary feed-dog and affording a fulcrum upon which said rock-lever is caused to follow the feeding and the rising and falling movements of the feed-bar, and means operatively connected with the feed-bar actuating means for tilting said rock-lever to vary the height of the operative surface of the auxiliary feed-dog relatively to that of the primary feed-dog.

3. In a sewing machine, the combination with a feed-bar, means for imparting rising and falling movements thereto, a primary feed-dog carried by said feed-bar, a feedrocker to which said feed-bar is pivotally connected, and means for actuating said feed-rocker, of a rock-lever, a fulcrum-pin for said rock-lever mounted upon and partaking of all the movements of said feedbar and disposed in substantial alinement with the operative surface of the primary feed-dog, an auxiliary feed-dog fixed upon said rock-lever, and a connection intermediate said rock-lever and the feed-rocker at a point of the latter offset from its pivotal connection with the feed-bar.

4. In a sewing machine, the combination with a feed-bar, means for imparting rising and falling movements thereto, a primary feed-dog carried by said feed-bar, a feedrocker to which said feed-bar is pivotally connected, and means for actuating said feed-rocker, of a rock-lever, a fulcrum therefor fixed upon said feed-bar, an auxiliary feed-dog fixed upon said rock-lever, and a link connection intermediate said rock-lever and the feed-rocker at a point of the latter offset from and in the direction of movement of its pivotal connection with the feedbar.

5. In a sewing machine, the combination with primary and auxiliary feed-bars pivotally connected together at a point in the direci tion of seam from their operative surfaces for bodily movement in unison, a primary feeddog carried by the primary feed-bar, and an auxiliary feed-dog fixed to the auxiliary feedbar, and solely controlled thereby in its relation with the primary feed-dog of common lifting means for imparting rising and falling movements to said feed-bars, a common actuating member for imparting feed ing movements to said feed-dogs, a pivotal connection intermediate the primary feedbarand said actuating member, and a link connection between the auxiliary feed-bar and said actuating member. l

6. In a sewing machine, the combination with a feed-bar, means for imparting rising and falling movements thereto, a primary feed-dog carried by said feed-bar, a feedrocker to which said feed-bar is pivotally connected, and means for actuating said feed-rocker, of a rock-lever, a fulcrum for said rock-lever carried by said feed-bar and disposed substantially between the pivotal connection of the same with the feed-rocker and the primary feed-dog, an auxiliary feeddrg fixed to said rock-lever, and means for imparting to said rock-lever tilting movements upon the feed-bar.

7. In a sewing machine, the combination with a feed-bar, a feed-rocker with which the same has a pivotal connection, a primary feed-dog carried by said feed-bar, means for imparting to said feed-bar rising and falling movements, and means for actuating said feed-rocker, of an auxiliary feed-dog movably connected with and deriving feeding movements from said feed-bar, a rocklever to which said auxiliary feed-dog is operatively connected and is adapted to receive rising and falling movements in relation to the primary feed-dog, a fulcrum-lever mounted for angular adjustment upon said feed-rocker, and a link connection intermediate said rock-lever and the fulcrum lever.

8. In a sewing machine, the combination with primary and auxiliary feed-bars pivotally connected together, a primary feeddog fixed upon the primary feed-bar, and an auxiliary feed-dog fixed upon the auxiliary feed-bar, of common lifting means for imparting rising and falling movements to said feed-bars, a feed-rocker for imparting feeding movements to said feed-dogs, a pivotal connection intermediate the primary feed-bar and said feed-rocker, a link connection between the auxiliary feed-bar and said feed-rocker at a point of said feedrocker offset from its connection with the Y primary feed-bar and adjustable in relation to the same, and actuating means for said feed-rocker including an adjusting device for varying the operativemovements of the same. p

9. In a sewing machine, the combination with primary and auxiliary feed-bars mounted for relative movement, a primary feed-dog carried by said primary feed-bar and an auxiliary feed-dog carried by said auxiliary feed-bar, of means for imparting to said feed-bars rising and falling movements, a feed-rocker, means for actuating said feed-rocker, a pivotal connection'intermediate said primary feed-bar and the feedrocker, a lever carrying a fulcrum-pin mounted upon said feed-rocker and adjustable thereon to bring its fulcrum-pin into different angular relation with its axis of motion, and a connection intermediate the auxiliary feed-bar and said fulcrum-pin whereby differential rising and falling movements are imparted to the auxiliary feed-dog in relation to the primary feed-bar.

l0. In a sewing machine, the combination with primary and auxiliary feed-bars mounted for relative movement, a primary feed-dog carried by said primary feed-bar and an auxiliary feed-dog carried by said auxiliary feed-bar, of means for imparting to said feed-bars rising and falling movements, a feed-rocker, means for actuating said feed-rocker, a pivotal connection intermediate said primary feed-bar and the feed-rocker, a lever pivotally mounted upon said rocker at one side of its axis of motion and carrying at one end a fulcrum-pin and provided with an oppositely extending finger, an adjusting screw also carried by said rocker and adapted to engage the finger of said lever, and a connection intermediate the auxiliary feed-bar and said fulcrum-pin:

auxiliary feed-bar, of means for imparting to said feed-bars rising and falling movements, a feed-rocker, means for actuating said feed-rocker, a pivotal connection intermediate said primary feed-dog and the feed-rocker, a lever pivotally mounted upon said rocker at one side of its axis of motion and carrying at one end a fulcrum-pin and provided with an oppositely extending finger, an adjustingscrew also carried by said rocker and adapted to engage the finger of said lever, a set-screw for securing said lever in its several positions of adjustment upon said rocker, and a connection intermediate the auxiliary feed-bar and said fulcrum-pin whereby differential rising and falling movements are imparted to the auxiliary feed-dog in relation to the primary feed-bar.

12. In a sewing machine, the combination with stitch-forming mechanism, a primary and an auxiliary feed-dog, means for imparting to said vfeed-dogs differential operat-ive movements, and a throat-plate provided with a needle-hole and adjacent apertures for said feed-dogs, of a presser-foot comprising a shank and a toe portion rigidly connected therewith and overlying said primary feed-dog, and a heel portion yieldingly connected with said shank and formed with an operative face having a channel disposed above the auxiliary feeddog, and a longitudinal rib overlying the adjacent margins of said feed-dog and the throat-plate adjacent the feed-dog aperture.

13. In a sewing machine, the combination with stitch-forming mechanism, a primary and an auxiliary feed-dog, means for imparting to said feed-dogs differential operative movements, and a throat-plate provided with a needle-hole and adjacent apertures for said feed-dogs, of a presser-foot comprising a shank and a toe portion rigidly connected therewith and overlying said primary feed-dog, and a heel port-ion yieldingly connected with said shank and formed with an operative face having a channel disposed above the auxiliary feeddog, and spaced longitudinal ribs at opposite sides of said channel, one of which overlies the adjacent margins of said feeddog and the throat-plate adjacent the feeddog aperture.

14. In a sewing machine, the combination with stitch-forming mechanism, a primary and an auxiliary feed-dog, means for imparting to said feed-dogs differential operative movements, and a throat-plate provided with a needle-hole and adjacent apertures for said feed-dogs, of a presser-foot comprising a shank and a toe portion rigidly connected therewith and overlying said primary feed-dog, an auxiliary heel portion overlying the auxiliary feed-dog and pivotally connected with said shank at the rear and provided with an upwardly extending stop finger normally resting in contact with said shank, and a spring interposed between said shank and the heel portion forward of its pivotal connection.

l5. In a sewing machine, the combination with stitch-forming mechanism, a primary and an auxiliary feed-dog, means for imparting to said feed-dogs differential operative movements, and a throat-plate provided with a needle-hole and adjacent apertures for said feed-dogs, of a presser-foot comprising a shank and a toe portion rigidly connected therewith and overlying said primary feed-dog, an auxiliary heel portion overlying the auxiliary feed-dog and pivotally connected with said shank at the rear and provided with an upwardly extending stop finger normally restingin contact with said shank, a spring interposed between said shank and the heel portion forward of its pivotal connection, and means for adjusting the tension of said spring.

16. In a sewing machine, the combination with stitch-forming mechanism, a primary and an auxiliary feed-dog, means for imparting to said feed-dogs equal feeding movements, means for imparting to said feed-dogs differential lifting movements, and a throat-plate provided with a needlehole and adjacent apertures for said feeddogs, of a presser-foot comprising a shank and a toe portionl rigidly connected therewith and overlying said primary feed-dog, and a spring-depressed heel portion overlying said auxiliary feed-dog and pivotally connected with said shank and provided with a stop normally engaging the latter to limit the downward movement thereof.

17. In a sewing machine, in combination, a main-shaft, feed-actuating and feed-lifting eccentrics thereon, a rocking member mounted upon a fixed fulcrum and having a laterally slotted segmental arm and an upright arm, an eccentric-rod embracing said feed-actuating eccentric and connected with the upright arm of said rocking member, a feed-rocker also mounted upon a fixed fulcrum and having a lateral and an upright arm, a link pivotally connected at one end with the lateral arm of said rocker and provided at the other end with an adjustable connection with the lateral segmental arm of said rocking member, a feeddog, a feed-bar by which the same is carried and having a pivotal connection with the upright arm of said feed-rocker, and a supporting link embracing the feed-lifting eccentric upon the main-shaft and having a pivotal connection with said feed-bar.

18. In a sewing machine, in combination, a main-shaft, feed-actuating and feed-lifting eccentrics thereon, a rocking member mounted upon a iiXed fulcrum and having a laterally slotted segmental arm and an upright arm, an eccentric-rod embracing said feed-actuating eccentric and connected with the upright arm of said rocking member, a feed-rocker also mounted upon a fixed fulcrum and having a lateral and an upright arm, a link pivotally connected at one end with the lateral arm of said rocker and provided at the other end with an adjustable connection with the lateral segmental arm of said rocking member, a feed-bar having a pivotal connection with the upright arm of said feed-rocker, a supporting link embracing the feed-lifting eccentric upon the main-shaft and having a pivotal connection with said feed-bar, two relatively movable feed-dogs mounted upon said feedbar, and an operative connection intermediate one of said feed-dogs and said feedrocler at a point laterally disposed in relation to its pivotal connection with said feedbar.

19. In a sewing-machine, in combination,

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with the lateral arm of said rocker and provided at the other end with an adjustable connection with the lateral segmental arm oi" said rocking member, a feed-bar having a pivotal connection with the upright arm of said feed-rocker, a support-inglink embracing the feed-lifting eccentric upon the mainshaft and having a pivotal connection with l said feed-bar', two relatively movable feeddogs mounted upon said feed-bar, a later-V ally adjustable fulcrum carried by said Jfeed-rocker, and an operative connection intermediate said fulcrum and one of sait feed-dogs. j Y

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

ALFRED GRIEB.

Witnesses: V

H. A. KORNEMANN, Jr., JOSEPH F. JAQUITH.

Washington, ZD. C. 

